Willingham hit .294/.435/.353 with three runs and one RBI in 17 at-bats before the injury. He remains without a timetable.
Rowland-Smith appeared in six games for the Diamondbacks, allowing four earned runs on seven hits and four walks in 7 1/3 innings of work.
Ross has been on the disabled list since the start of the season, but appeared in nine minor-league rehab games for Triple-A Reno before being activated. He hit .290 with one extra-base hit in those nine games.
Headley was hoping to return Friday when asked by UT-San Diego Thursday, but he will have to wait until at least Saturday's game now.
A pair of injured
Freese has struggled mightily this season. The former World Series hero owns a disturbing stat line of .151/.207/.208 and has just four hits in his last 35 at-bats.